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We narrowed to 1,042 results for: URE

Showing: 141 - 160 of 1042 results
  1. Twenty Years of Sharing: Expanding Accessibility

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    Blog Post
    ...India at room temperature. Partnering with our distributor allowed us to ensure that temperature-sensitive...kept at the appropriate temperature for the duration of their journey. Figure 2: Annual distribution ...from that country. Stats and figures are helpful, but our favorite measure of our educational resources...from our repository to an amazing 111 countries (Figure 1)! But while we were making the materials available... the accessibility varied country to country.   Figure 1: Number of countries Addgene distributes to per...”: a distributor who, among other things, could ensure our packages navigated customs and arrived at their...destination in a timely manner and at the correct temperature. To date, we have partnered with six distributors...
  2. Getting the Most from Your Lentiviral Transduction

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    Blog Post
    ...the age of your culture post thaw. In general, the higher the passage number of a culture the lower the ...growth, or clumping. To ensure the best possible results for any tissue culture-based experiment, labs ... & Chen, T.R. “Mycoplasma infection of cultured cells.” Nature 339 (1989). 487–488. PubMed PMID: 2725683...packaging cells and your target cells. Poor tissue culture practices can lead to low titers and poor transductions...transductions. Cell lines should be routinely subcultured at densities that are low enough to prevent confluency... high enough to promote cell growth. Overgrown cultures stimulate quiescence, the resting phase of the...the transfection and transduction efficiencies. Cultures should only be passaged 20-30 times before discarding...
  3. Design Tips for Prime Editing

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    Blog Post
    ...secondary structures in your pegRNA could inhibit editing (Anzalone et al., 2019). Figure 2: Starting...disrupting its canonical structure and Cas9 binding (Nishimasu et al., 2014). Figure 3: pegRNAs whose ...genome, ensure it is not homologous to the target genomic sequence (Chen et al., 2021). Figure 8: ..., N., Ishitani, R., Zhang, F., & Nureki, O. (2014). Crystal Structure of Cas9 in Complex with Guide RNA...RT) template including the desired edit. Figure 1: Prime Editing schematic. Created with BioRender.com...this location bind to Cas9 with canonical sgRNA structure (right). Created with BioRender.com. What ...lead to indels (Anzalone et al., 2019). Figure 4: Editing the PAM prevents the prime editor from...
  4. Hot Plasmids: Summer 2024

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    Blog Post
    ...cryo-EM grid.     Figure 1: MagIC-cryo-EM for sample enrichment and structure determination. A) Schematic... this post: MagIC-Cryo-EM for enrichment and structure determination LEA proteins protect samples during...astrocytes MagIC-Cryo-EM for sample enrichment and structure determination By Mike Lacy Conventional cryogenic...that combines enrichment and imaging of proteins captured on magnetic beads (Arimura et al., 2024). In MagIC-cryo-EM...GFP fusion in this proof-of-concept study) are captured on streptavidin-coated magnetic beads through ...and spacer proteins ending with a GFP nanobody (Figure 1). This enrichment streamlines the purification...bundle; SAH: 60-nm single alpha helix) and target capture module (SpyTag-GFP nanobody) assembled on beads...
  5. Tips for a 1st Time CRISPR User (by a 1st Time CRISPR User)

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    Blog Post
    ...Then, mix the PCR products and use temperature to denature and renature the dsDNA. Upon renaturation, you...confirm your results. (Figure 5). The digestion product (Figure 4, lanes 0.3 % 3.0, Figure 5, lane 2) is faint...expression was across the different cells (Figure 3).   Figure 2: Cas9 expression in monoclonal cell...comparing it to the undigested control (Figure 4, lane 0, Figure 5, lane 1) is what confirms it’s a real...Cas9 lentiviral vector, lentiCas9-Blast (52962-LV, Figure 1). Some cells were then used to generate a monoclonal... The rest of the cells were frozen down. Figure 1: Cas9 expression in A549 cells transduced with... cell pool had wildly variable Cas9 expression (Figure 1). This is a problem because Cas9 expression affects...
  6. Developing Lab Management Software for Biology

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    Blog Post
    ...into the appropriate stab culture Grow the stab culture Ship the stab culture to the proper location To...Every single step in a lab procedure can and will fail. Some step failures require re-attempting the same...do when something fails. While we’re sure our techs could figure it out if they needed to, they’d have...interested to see which part of her procedures are the most failure prone. In an academic lab, a similar...data for lab procedures. With this data in hand, we can go back and optimize our procedure to make the ...To keep ourselves from mixing up samples and to ensure that everything is grown successfully, we must ...following code examples show how software can be structured to allow for the messiness of biology. These ...
  7. Tips for Titering Your Lentiviral Preps

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    Blog Post
    ...particles. Direct measurement of lentiviral RNA is one alternative to direct p24 measurement. Like a p24 ELISA...that specific feature. Primers targeting the transgene are also beneficial as they ensure that the correct...stable cell line. While we’ve all experienced the pressure to move a project forward, transductions should...time to properly titer your virus will not only ensure that your infection is designed in the best possible...flavors, physical or functional. Physical titers measure the amount of viral particles in a sample and are...acid. Functional titers, or infectious titers, measure how many of the viral particles produced can actually...common assays for physical titer are direct p24 measurements via ELISA and qPCR for viral RNA. Measuring ...
  8. Antibodies 101: Normalization and Loading Controls for Western Blots

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    Blog Post
    ...blot.   Total protein measurements as loading controls Total protein measurements are an accurate alternative...control measurement will take place either before or after blotting for your POI. Figure 6: Total...the most important feature of a loading control, and both total protein measurements are linear. Note the... a western blot requires a standard curve with a pure sample of your protein of interest (POI). This approach...pipetting or irregular membrane transfer. Figure 1: A loading control is a type of positive control... and the resulting fraction is reported. Figure 2: Normalization with loading controls. Under each...experimental design and gel quantification. Figure 3: In a perfect world, protein concentration in...
  9. Antibodies 101: Antibody Engineering and Directed Evolution

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    Blog Post
    ... to the versatility of the basic antibody structure (Figure 1). Antibodies can be broken up into smaller...purpose. Figure 1: Overview of antibody engineering methods. (A) Basic structure of an antibody.... sections. Structure-guided directed evolution If you desire a bit more control, structure guided directed...is the modification of antibody sequences and structures to affect their function. Usually, the goal is... PCR, degenerate primers, gene shuffling, and structure-guided directed evolution. The nice thing about...they all follow the same general cyclical process (Figure 2). The differences typically come in when generating... the starting point for the next cycle. Figure 2: General process of antibody directed evolution...
  10. Antibodies 101: Producing Recombinant Antibodies

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    Blog Post
    ...other materials have been washed away (Figure 1).      Figure 1: The steps of rAb production. Created... make sure to look up the setting for your isotype.  Antibody concentration may also be measured through...antibodies with some molecular biology and cell culture experience. Let’s go over the basics of making ... days (in mammalian cells) to collect the cell culture supernatant for further processing. It may be helpful...appropriate immobilized ligands are incubated with cell culture supernatant containing antibodies. The antibodies...your antibody in a downstream step, you’ll want to ensure that your buffer components are compatible with...have an IgG protein setting. If yours does not, be sure to set the absorbance to 280 nm (Pace et al., 1995...
  11. Which Fluorescence Microscopy Technique is Best for Me?

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    Blog Post
    ... view is excited at one time and captured in a single camera exposure. This is much faster than relying...the Harvard Center for Biological Imaging and a Lecturer on Molecular and Cellular Biology at Harvard University...an x-ray, or a biologist imaging the smallest structures of life; the key to a great image is contrast...relatively thicker three dimensional sample (see Figure 1); similar to an MRI or CT scanner. This is accomplished...resolution) limit of a light microscope. Due to the wave nature of light, an infinitely small point of light will...improvement in the resolution of a light microscope (see Figure 1). What microscopy technique should I use for ...live cells with fluorescently labelled, motile structures These samples are thin enough to sit within the...
  12. Hot Plasmids: Fall 2025

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    Blog Post
    ...proteins with a membrane-impermeable biotin substrate (Figure 1). Biotinylated proteins were isolated, identified...shared proteome of astrocytes and neurons (CS SPAN) featured extracellular matrix proteins, cell adhesion molecules...transporters, ion channels, GPCRs, and more.  Figure 1: Workflow for cell-surface protein labeling and...Huntington's disease model) will be valuable resources for future studies of the molecular bases of astrocyte-neuron...recipient cells from red to green fluorescence (Figure 2). Donor cells express iCre with a mitochondrial...DsRed-STOP to trigger expression of EGFP. Figure 2: Schematic of the MitoTRACER system. NLS = nuclear...The power and potential of mitochondria transfer. Nature, 623(7986), 283–291. https://doi.org/10.1038/s41586...
  13. Antibodies 101: Immunoprecipitation

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    ...perform the IP at 4oC. When choosing the capture antibody for IP, be sure to choose one that recognizes the ...target protein/capture antibody intact. The wash step is repeated several times to ensure non-specific ...complexes, wash away unbound protein, elute and measure the target. However, the two different approaches...process of anchoring an antibody, often called the capture antibody, to agarose or magnetic beads in a way...immunoglobulin, leaving the antigen binding sites free to capture the target protein. The beads can be collected ...Agarose beads are sponge-like and vary in shape and structure. Their porous surface provides a large area for...protein interactions, and limit high throughput procedures. However, agarose beads are often a more cost-effective...
  14. Addgene's Tips for Plasmid Quality Control

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    Blog Post
    ... your culture should always be derived from a single colony to ensure uniformity of the culture. Sequencing...to a shared computer or server. This will ensure that future members of your lab can access and use the...depending on the number of features we need to verify. Determining which features to verify will depend on...important features that differentiate this plasmid from its predecessor. Important features may include...reaction, or about 250 amino acids worth, so make sure the feature you want to verify is within this range. Read...plasmids, such as special growth instructions (temperature, strain, media supplements), suggested sequencing...information in a binder or digital notebook and make sure you note the freezer location of every plasmid in...
  15. Antibodies 101: ELISA (Enzyme-linked Immunosorbent Assay)

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    Blog Post
    ...antibodies. Figure 1: Overview of using Sandwich ELISA to quantitatively measure protein concentration...format. Figure 2: Overview of using Competitive ELISA to quantitatively measure protein concentration...the plate. Figure 3: Overview of using Direct ELISA to quantitatively measure protein concentration...proteins. Figure 4: Overview of using Indirect ELISA to quantitatively measure protein concentration...competitive ELISA use antibodies coating the wells to capture antigen from a sample, whereas antigen is bound...coating the wells of a flat bottomed plate with a capture antibody that is specific to the protein you are...that also recognizes the same target protein. The capture antibody and the detection antibody recognize different...
  16. Viral Vectors 101: Systemic Capsids

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    Blog Post
    ...organism to target large or diffuse biological structures. Of primary interest here are systemic capsids...health. While it’s always helpful to start with a literature search to see what others have done, you’ll need... before using it in an application.     Figure 1: AAV toolkit for targeted gene delivery to the... antibodies developed in response to the first exposure to AAV9. The exception is the X1 capsid for targeting...strains. It is therefore important to review the literature for use of a capsid in your strain of interest...to start selecting and testing systemic capsids! Figure 2 contains a decision tree for selecting a capsid...further highlighted below the table.     Figure 2: This decision tree can help guide your choice...
  17. Some Like it Hot: Thermostable GeoCas9

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    Blog Post
    ...elevated temperatures. In both cases, GeoCas9 outperformed SpCas9 at high temperatures. See Figure 1 for ...stearothermophilus grows at temperatures ranging from 30-74 °C, with an optimal growth temperature of 55 °C. For a... longevity. GeoCas9 is active at high temperatures Figure 1: Thermostability of SpCas9 vs GeoCas9... These Cas9 proteins don’t work well at high temperatures, so to use them in thermophiles, bacteria must... to make eSpCas9 and SpCas9-HF1. By mining the treasure trove of naturally occurring Cas9 diversity via...CRAA (R = A or G) Spacer Length 20 nt 22 nt Temperature Range for Optimal Activity 35 - 45 °C 50 - 70...GeoCas9 RNPs were incubated in reaction buffer at temperatures ranging from 25-80 °C. Activity is expressed...
  18. Make a Splash: Notions of Scientific Impact Are Evolving

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    Blog Post
    ...publications really the best way to measure impact? As that Nature report also noted, papers detailing...scientific publications. Ventures like Impact Story seek to find ways to capture scholarly work that exists...scientific journals. Of course, no one measure will ever adequately capture a notion as complex as “scientific... you like to measure yours? More Reading Fenner M. "Altmetrics and Other Novel Measures for Scientific...Impact Measures" (2009) PLOS One 4(6): e6022. doi: 10.1371/journal.pone.0006022 Aragon AM. "A measure for...publish in journals with a high “impact factor,” a measure that dates back to 1975 and is based on the average...articles. Of course, a publication in Science or Nature is always nice, but in the wired world we are living...
  19. Hot Plasmids: Winter 2025

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    Blog Post
    ...packaging as a single payload (Figure 4). Figure 4: ONE-GO biosensors measure the formation of Gα-GTP...uses new combinations of PE protein components (Figure 1), an altered epegRNA delivered with an enhanced...amplification of cargo, and heat treatment.  Figure 1: Left: recombined prime editing tools PE2max-...heritable desired edits in tomato and Arabidopsis. Nature Plants, 10(10), 1502–1513. doi: https://doi.org...N-terminal CLIPf tag and a C-terminal SNAPf tag; see Figure 2), the authors developed a cost-effective expression...solution and when associated with microtubules. Figure 2: CLIP-SNAP fusion proteins for single-molecule... inserted. B) Protein expression and labeling procedure. Adapted from Smith et al. 2024 under a CC-BY ...
  20. A Guide to Starting Your Own Journal Club

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    Blog Post
    ...walks through the paper figure by figure. Some follow the same figure by figure organization with a different...adapt the second version (multiple presenter, figure by figure) if the primary purpose is training graduate...enjoy is discussion of current new and exciting literature. As I transitioned out of academia and away from...researchers of all varieties must stay current with literature and emerging technologies to remain competitive...in journal clubs. They also have likely had the pleasure of attending both productive and not so productive...pieces before that first meeting takes place to ensure success. One of the most important is letting people...ready for your first journal club to begin! Figure 1: Discussing next-generation sequencing at the...
Showing: 141 - 160 of 1042 results